Ornamental Miscanthus sinensis Plant Named &#39;M77&#39;

ABSTRACT

A new variety of Miscanthus sinensis plant named ‘M77’ produces a reduced number of seeds, making it less invasive.

Latin name of the genus and species of the plant claimed: ‘M77’ is a vegetatively propagated ornamental perennial Miscanthus cultivar of the genus and species Miscanthus sinensis.

Variety denomination: The new Miscanthus sinensis claimed is of the cultivar denominated ‘M77’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Miscanthus sinensis herein referred to as ‘M77’.

The new Miscanthus sinensis is a product of a planned research, evaluation, and testing program conducted by the Inventors in Tifton, Ga. The objective of the Miscanthus sinensis research program is to create a new plant cultivar with reduced seed production. This cultivar is commercially important for its superior ornamental value and low seed production. These and other qualities are enumerated herein.

There is a need for a seed sterile Miscanthus cultivar because Miscanthus cultivars produce higher seed set at higher elevations which tend to make this genus invasive. Unprotected roots of respective groups of 59, 44, and 49 Miscanthus sinensis ‘Gracillimus’ plants were irradiated with 4-, 8-, and 12-Kr, respectively, of Cobalt 60 radiation and transplanted to a test field at Tifton, Ga. on Apr. 21, 2006. On Aug. 9, 2006, 37 and 1 plants were observed to have survived the 4-Kr treatment, and one plant was observed to have survived the 8-Kr treatment. Seven plants from the 4-Kr treated plants had tillers with reduced seed set. One plant, designated 4-22-1-1, had tillers with no seed set. A culm from 4-22-1-1 was designated M8-4 in 2008 and observed for seed set thru 2009 at Tifton, Ga. (elevation about 350 ft.). In 2010, M8-4 was designated as M8 and planted at Blairsville, Ga. (elevation about 1,880 ft.) in 2010. In 2010, M8 produced one seed per inflorescence at Tifton, Ga. and no seed at Blairsville, Ga. while the Miscanthus sinensis ‘Gracillimus’ control plants produced numerous seeds per inflorescence at both locations in non-replicated tests. The seed sterile plant observed at Blairsville, Ga. (high elevation) was designated ‘M77’. This ‘M77’ plant was then asexually propagated by vegetative propagation. The resulting ‘M77’ plants were tested at Tifton, Ga. and Blairsville, Ga. in replicated tests from 2012 thru 2015. Tests consisted of five and three single plant replications arranged in a randomized complete block experiment at Tifton, Ga. and Blairsville, Ga., respectively.

Asexual reproduction of the new Miscanthus ‘M77’ by vegetative propagation (single stem propagules) in a controlled environment in Tifton, Ga. and Blairsville, Ga. since 2012, has shown that the unique features of this new Miscanthus sinensis cultivar are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent the characteristics of a new M. sinensis cultivar ‘M77’. The new cultivar ‘M77’ has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in, for example, temperature, day-length, light intensity, soil types, and water and fertility levels without, however, any variance in genotype.

Throughout this specification, color names beginning with a small letter signify that the name of that color, as used in common speech, is aptly descriptive. Color names beginning with a capital letter designate values based upon the R.H.S. Colour Chart, 5^(th) edition published by The Royal Horticultural Society, London, England.

The following traits have been repeatedly observed for the new M. sinensis cultivar ‘M77’ in Tifton, Ga. and Blairsville, Ga. and can be compared to M. sinensis

-   -   1. ‘M77’ plants produce few seeds, especially at high         elevations.     -   2. ‘M77’ plants exhibit a vigorous growth habit.     -   3. ‘M77’ plants are highly seed sterile.

The new cultivar Miscanthus ‘M77’ can be compared to its parent, Miscanthus sinensis var. Gracillimus.

Plants of the new Miscanthus ‘M77’ differ from its parent ‘Gracillimus’, at least in the following characteristic:

-   -   1. The new cultivar ‘M77’ produces significantly fewer seeds         compared to ‘Gracillimus’.

The following observations, measurements, and values describe plants grown in Tifton, Ga. and Blairsville, Ga. In Tables 1-7, the least significant difference (LSD) is set at P<0.05probability level. Growth days were included in ratings. Plants were spaced 2 meters center to center spacing. Plants were established as single stem propagules in mid-April to mid-May and rated in September through October. Data was taken from plants during year of establishment in 2012 at Tifton, Ga. and 2013 in Blairsville, Ga. Data were also taken in 2013 and 2014 from over-wintered 2012 and 2013 plants at Tifton, Ga. and in 2013 and 2015 from over-wintered 2012 plants at Blairsville, Ga.

Inflorescence height of the new cultivar ‘M77’ was significantly shorter than those of ‘Gracillimus’ in four of seven tests (Table 1). Height of the leaf canopy of ‘M77’ was significantly shorter than that of ‘Gracillimus’ in three of seven tests (Table 2). Canopy diameter was significantly narrower for ‘M77’ compared to ‘Gracillimus’ in only two of seven tests (Table 3). This appeared to be related to the year of establishment. There appeared to be only small differences in canopy diameter between ‘M77’ and ‘Gracillimus’ after the year of establishment. As expected, plants tended to become more robust as they become older. Differences in inflorescence length appeared to be small between the ‘M77’ and ‘Gracillimus’ and significant only in two of three years at Tifton, Ga. (Table 4). ‘M77’ usually had fewer inflorescences than ‘Gracillimus’, but this trait was significant in only three of seven tests (Table 5). Inflorescence number appeared to vary greatly from plant to plant (probably environmental effects). Leaf length and width were similar for ‘M77’ and ‘Gracillimus’ (Table 6). However, leaves of ‘Gracillimus’ were significantly longer than those of ‘M77’ at Tifton in 2013. The data shows (Table 7) that seed set was greatly reduced for ‘M77’ compared to ‘Gracillimus’ and statistically significant for all years tested.

Although ‘M77’ sets a small amount of seed, we wanted to know how many of the seed produced actually germinated. In 2015, we tested the germination of 2014 harvested seed from ‘M77’ plants from both Tifton, Ga. and Blairsville, Ga. Note: a very large number of inflorescences of ‘M77’ needed to be harvested at Tifton, Ga. and Blairsville, Ga. in order to get enough seed to germinate of this cultivar. None of the seed from the Tifton, Ga. harvest germinated while only 32% of the seed harvested at Blairsville, Ga. germinated (Table 7), further demonstrating high seed sterility. This characteristic reduces the invasive potential of ‘M77’, which is especially needed at higher elevations. Seeds were stored in small kraft envelops in the threshing shed for six months. Seeds were then planted in steam-sterilized soil and allowed to germinate for 45 days. During the germination period the seeds went through random wet and dry periods. Seedling emergence was rated at three dates during this period. In 2015, we also tested 75 and 12 clones of ‘M77’ at Tifton, Ga. and Blairsville, Ga., respectively, for morphological uniformity and seed set. All were seed sterile and morphologically uniform.

TABLE 1 Height of inflorescence of two Miscanthus sinensis ornamental grasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Tifton, GA Blairsville, GA 2012/ 2013/ 2012/ 2012/ 2012/ Entry 2012 2013 2014 2014 2013 2013 2015 Growth 180 182 197 197 154 116 162 Days ‘M77’ 122 111 133 203 200 122 184 ‘M90’ 145 143 136 208 212 144 210 LSD 11 10 NS NS 12 11 NS

In Table 1, plant height measured from ground level to top of inflorescence. All heights measured are in cm. At Tifton, Ga., ‘M77’ and ‘Gracillimus’ were planted 18 Apr. 2012 and 13 Apr. 2013 and measurements were taken 15 Oct. 2012, 30 Sep. 2013, and 09 Sept. 2014, respectively. At Blairsville, Ga., ‘M77’ and ‘Gracillimus’ were planted 14 Apr. 2012, and 16 May 2013, and measurements taken 09 Sep. 2013 and 24 Sep. 2015, respectively. Single year is year planted and year data recorded; double years are “year planted/year data recorded”.

TABLE 2 Height of leaves of two Miscanthus sinensis ornamental grasses (‘M77’ = experimental and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Tifton, GA Blairsville, GA Entry 2012 2012/2013 2013/2014 2012/2014 2012/2013 2013 2012/2015 Growth 180 182 197 197 154 116 162 Days ‘M77’ 66 67 106 136 122 66 151 ‘M90’ 90 76 100 140 144 89 140 LSD 11 NS NS NS 11 10 NS

In Table 2, height of leaves were measured from ground level to top of leaf canopy. All height measurements are in cm. At Tifton, Ga., tests were planted 18 Apr. 2012 and 13 Apr. 2013 and measurements were taken 15 Oct. 2012, 30 Sep. 2013, and 09 Sep. 2014. At Blairsville, Ga., tests were planted 14 Apr. 2012, and 16 May 2013, and measurements were taken 09 Sep. 2013 and 24 Sep. 2015. Single year designation is year planted and year data recorded; double years designations are “year planted/year data recorded”.

TABLE 3 Canopy diameter of two Miscanthus sinensis ornamental grasses (‘M77’ = experimental and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Tifton, GA Blairsville, GA 2012/ 2013/ 2012/ 2012/ 2013 2014 2014 2013 2014 2015 ‘M 77’ 58 91 151 100 54 184 ‘M 90’ 66 88 153 135 128 159 LSD NS NS NS 25 20 NS GD 182 197 197 116 130 162

Canopy diameter measurements are the average diameter of the widest and the narrowest diameter of a single plant canopy. All canopy measurements are in cm. At Tifton, Ga., tests planted were 18 Apr. 2012 and 13 Apr. 2013 and measurements were taken 30 Sep. 2013, and 09 Sep. 2014. At Blairsville, Ga., tests were planted 14 Apr. 2012, and 16 May 2013, and 15 May 2014 and measurements taken 09 Sep. 2013, 22 Sep. 2014 and 24 Sep. 2015. Single year designation is year planted and year data recorded; double years designations are “year planted/year data recorded”.

TABLE 4 Inflorescence lengths of two Miscanthus sinensis ornamental grasses ‘(M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Tifton Blairsville 2012 2012/2013 2013 2012/2013 2012/2015 Growth 180 182 116 154 162 Days ‘M77’ 20 36 20 33 28 ‘M90’ 26 35 25 32 29 LSD 2 NS 2 NS NS

At Tifton, Ga., tests were planted 18 Apr. 2012 and 13 Apr. 2013 and measurements were taken 15 Oct. 2012, and 30 Sep. 2013. At Blairsville, Ga., tests were planted 14 Apr. 2012, and 16 May 2013, and measurements were taken 09 Sep. 2013 and 24 Sep. 2015. All canopy measurements are in cm. Single year designation is year planted and year data recorded; double years designations are “year planted/year data recorded”.

TABLE 5 Number of inflorescences of two Miscanthus sinensis ornamental grasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Tifton, GA Blairsville, GA 2012/ 2013/ 2012/ 2012/ 2012/ 2012 2013 2014 2014 2013 2013 2015 GD 180 182 197 197 154 116 162 ‘M77’ 23 20 103 86 81 21 133 ‘M90’ 34 57 95 127 108 83 153 LSD 17 NS NS 23 NS 37 NS

At Tifton, Ga., tests were planted 18 Apr. 2012 and 13 Apr. 2013 and measurements taken 15 Oct. 2012, 30 Sep. 2013, and 09 Sep. 2014. At Blairsville, Ga., tests were planted 14 Apr. 2012, and 16 May 2013, and measurements were taken 09 Sep. 2013 and 24 Sep. 2015. Single year designation is year planted and year data recorded; double years designations are “year planted/year data recorded”.

TABLE 6 Leaf length and width of two Miscanthus sinensis ornamental grasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Tifton, GA Blairsville, GA Tifton, GA Blairsville, GA Length Length Width Width 2012/2013 2012/2015 2012/2013 2012/2015 Growth 182 162 182 162 Days ‘M 77’ 44 68 4.37 5.2 ‘M 90’ 53 52 4.57 5.5 LSD 6 NS NS NS

At Tifton, Ga., test was planted 18 Apr. 2012 and measurements were taken 30 Sep. 2013. Leaf length (average from 3 culms) was measured from the leaf collar to the leaf tip of the latest fully extended leaf. At Blairsville, Ga., test was planted 14 Apr. 2012 and measurements were taken 24 Sep. 2015. Leaf width (average from 3 culms) was measured in the center of the latest fully extended leaf. Leaf length measurements are in cm. Leaf width measurements are in mm. Double year designations indicate “year planted/year data recorded”.

TABLE 7 Seed set of two Miscanthus sinensis ornamental grasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Seeds per Inflorescence Tifton, GA Blairsville, GA Seed Germination - % 2012/ 2012/ 2012/ 2012/ 2012/ Tifton Blairsville Entry 2013 2014 2015 2013 2014 2015 2014 2014 ‘M77’ 0.0 7 0 0.02 0.4 0 0 32 ‘M90’ 0.02 256 588 24 51 138 42 70 LSD 0.0 2 129 0.0 0.0 0.0 17 15

At Tifton, Ga., tests were planted 18 Apr. 2012 and 12 May 2015 and seeds were harvested in Oct. of 2013, 2014 and 2015. At Blairsville, Ga., test was planted 14 Apr. 2012, and seeds were harvested in Oct. 2013. 2014 and 2015. Number of seeds per inflorescence was determined from the mean of four random inflorescences from each replication. Seed germination tests was conducted on 25 seeds from four and three different plants (replicatons) harvested in Oct. 2014 at Tifton and Blairsville, Ga. Germination tests were conducted in April of 2015 to allow seeds to go through a dormancy period and simulate field conditions. Double year designations indicate “year planted/year data recorded”.

TABLE 8 Summary of morphological characteristics of two Miscanthus sinensis cultivars. Trait ‘Gracillimus’ ‘M77” Mature inflorescence 136-210 cm 111-203 cm height Mature leaf height 76-144 cm 66-151 cm Diameter of plant canopy 66-159 cm 54-184 cm Inflorescence length 25-35 cm 20-36 cm Number of Inflorescences 34-153 23-133 per plant Leaf width 4.6-5.5 mm 4.4-5.2 mm Leaf length 52-53 cm 44-68 cm Adaxial leaf surface Glaborous Glabrous trichomes Abaxial leaf surface 4-6 mm long Sparse, less than trichomes 0.5 mm long Leaf blade margin Abundant, less than Abundant, less than trichome length 0.5 mm long 0.5 mm long Leaf collar trichomes Dense, 4-6 mm long Dense, 3-5 mm long Sheath trichomes Less than 0.5 mm long Scattered, less than 1 mm long Ligule Yes. 1-2 mm Yes, 1-2 mm Ligule trichomes Dense, 3-4 mm long Dense, 3-4 mm long Sheath trichomes Less than 0.5 mm long Abundant, less than 1 mm long Adaxial leaf color 143A 143A Abaxial leaf color 143A 143A Midrib color NN155D NN155D

In summary, ‘M77’ is similar to ‘Gracillimus’ in height, canopy width, inflorescence length, and leaf characteristics. ‘M77’ produce significantly fewer seeds than ‘Gracillimus’ which should greatly reduce the invasiveness of this species.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying colored photographs illustrate the overall appearance and distinct characteristics of the new cultivar of Miscanthus ‘M77’. The colors in the photographs are as close as possible with the photographic and printing technology utilized.

Certain characteristics of this variety, such as growth and color, may change with changing environmental conditions (e.g., light, temperature, moisture, nutrient availability, or other factors). Color descriptions and other terminology are used in accordance with their ordinary dictionary descriptions, unless the context clearly indicates otherwise. Color designations are made with reference to The Royal Horticultural Society (R.H.S.) Colour Chart (5^(th) edition, 2007).

FIG. 1 is a photograph of the vegetative stage of the new cultivar Miscanthus ‘M77’.

FIG. 2 is a photograph of the flowering stage of the new cultivar Miscanthus ‘M77’.

The new cultivar ‘M77’ is a vigorous perennial at Blairsville, Ga. (USDA Zone 7a). The new cultivar ‘M77’ survived 90, 95, and 101 days below 0 ° C. and low temperatures of −9, −29, and −17° C. for the winters of 2012/2013, 2013/2014, and 2014/2015, respectively at Blairsville, Ga.

All data are from plants established as single stem propagules in mid-April to mid-May and rated in September through October, except the double year dates in the previous tables indicate “year of establishment/year data was collected”.

-   Plant:     -   -   Mature inflorescence height.—111-203 cm.         -   Mature leaf height.—66-151 cm.         -   Diameter of plant canopy.—54-184 cm.         -   Inflorescence length.—20-36 cm.         -   Number of Inflorescences per plant.—23-133. -   Leaf:     -   -   Leaf width.—4.4-5.2 mm.         -   Leaf length.—44-68 cm.         -   Adaxial leaf surface trichomes.—Glabrous.         -   Abaxial leaf surface trichomes.—Sparse, less than 0.5 mm             long.         -   Leaf blade margin trichome length.—Abundant, less than 0.5             mm long.         -   Leaf collar trichomes.—Dense, 3-5 mm long.         -   Sheath trichomes.—Scattered, less than 1 mm long.         -   Ligule.—Yes, 1-2 mm.         -   Ligule trichomas.—Dense, 3-4 mm long.         -   Sheath trichomes.—Abundant, less than 1 mm long.         -   Adaxial leaf color.—143A.         -   Abaxial leaf color.—143A.         -   Midrib color.—NN155D. 

What is claimed is:
 1. A new and distinct cultivar of the Miscanthus plant named ‘M77’, as herein illustrated and described: 